Low-Carb Lies: Why Your Diet Is Sabotaging Your Fitness
- sarah-jane956
- Sep 17
- 3 min read

Meet Sarah: Fit, Focused... and Fatigued?
Sarah, 47, is a committed runner and marketing executive navigating perimenopause. For years, she followed a strict low-carb diet—protein shake for breakfast, grilled chicken salad for lunch, and fish with veggies for dinner. Initially, she lost weight and felt energized.
But over time, her performance declined, sleep suffered, and mood swings crept in.
Concerned, she met with a sports nutritionist—and discovered she was running on fumes due to low carbohydrate availability (LCA).
Why Carbs Are Critical—Especially for Active People
Think of carbs as premium fuel for your body. Just like a high-performance car runs best on high-octane gas, your body performs best with sufficient carbohydrates. When you don’t get enough, especially during intense workouts, performance plummets and recovery suffers.
Low-carb intake leads to:
Decreased endurance
Reduced strength and power
Impaired mental clarity during workouts
Increased cortisol (your body’s stress hormone)
The Female Factor: Carbs & Hormonal Health
Low-carb diets are especially risky for women in perimenopause or menopause. Inadequate carbs can worsen hormonal imbalances, triggering:
Sleep disturbances
Mood swings
Bone density loss
Slower metabolism
Carbs vs. Cortisol
When you cut carbs, cortisol rises. For women already experiencing elevated cortisol from hormonal shifts, this spells trouble. It can also sabotage fat loss efforts—ironically, the very thing many are hoping to achieve with low-carb dieting.

Case Study 2: Tom’s Ride to Recovery
Tom, 52, a software engineer and avid cyclist, also adopted a low-carb lifestyle. While aiming to lose weight, he instead experienced:
Fatigue on group rides
Brain fog at work
Persistent belly fat
His nutritionist pointed out that low carb intake can lower testosterone and increase cortisol—two things that blunt performance and recovery in men.
How Sarah and Tom Rebounded—And How You Can Too
1. Calculate Your Carb Needs
Aim for 3.5 to 7 grams of carbs per kg of body weight daily (1.6–3.2g/lb).
Sarah: 5g/kg
Tom: 4g/kg
2. Fuel Your Workouts
Eat carbs before and after training.
Sarah added oatmeal with fruit pre-run
Tom started eating a banana with peanut butter pre-ride
3. Spread Carbs Across Meals
Include carbs at every meal—about 25% of your daily needs—to keep energy levels stable.
4. Prioritize Post-Workout Refueling
Replenish with at least 1.2g of carbs/kg (0.55g/lb) after intense sessions. Recovery smoothies work wonders.
5. Adjust for Your Life Stage
Women: Use carbs to manage cortisol and support hormonal balance
Men: Maintain healthy testosterone levels with adequate carbs
6. Choose Quality Carbs
Go for complex carbs like sweet potatoes, quinoa, whole grains, and berries.
7. Listen to Your Body
Tweak your carb intake based on how you feel, train, and recover.
The Results: Energy, Endurance, and Empowerment
Within weeks of adjusting their carb intake:
Sarah crushed her previous 10K time and slept better than she had in years.
Tom regained his cycling stamina and mental sharpness.
Neither gained fat—just strength, clarity, and vitality.
The Takeaway: Carbs Aren’t the Enemy—They’re the
Answer
If you're 40+ and active, carbs are not a threat—they're essential. Fueling smartly can enhance every aspect of your health:
✅ Athletic performance
✅ Hormonal health
✅ Mood stability
✅ Long-term wellness
Let Beyond Fitness Help You Fuel Smarter
At Beyond Fitness, we specialize in training and nutrition for men and women over 40. If you're unsure how to fuel your body properly or feel your performance has plateaued, our expert coaches are here to help.
Need personalized nutrition guidance? Drop by or connect with one of our certified nutritionists. We’ll help you build a plan that supports your goals, age, and lifestyle.
Fuel Up, Perform Better, Feel Your Best.
Your best years are ahead—let’s power them with the right fuel.Visit us at Beyond Fitness or message us anytime. We’re with you every step of the way.
Contact us at Beyond Fitness and let us help you build your system.





Comments